Interview: Ludovic Uhring-Cadart, R&D manager at Focal

Ludovic Uhring-Cadart is an Electro-Acoustical engineer and the R&D Director for Focal’sHeadphones and Professional Audio divisions. He has contributed to the development of the brand’s headphones, especially the Utopia.

What inspired Focal to begin designing and manufacturing headphones?

We wanted to reach a larger number of audiophiles and music lovers while also building a new audience. After 35 years of research, Focal has earned its reputation thanks to the high-quality sound produced by its drivers, passive speakers and monitoring speakers. We are confident that our expertise, mastery of driver design, and continuous research all contribute to our ability to manufacture excellent headphones.

Does Focal also manufacture the drivers installed in its hi-fi headphones?

We design all the drivers for our headphones. The drivers used for our Utopia, Elear and Clear headphones are manufactured in Saint-Étienne, where we have a dedicated production line. The manufacturing process requires precision and meticulous attention to detail, and we have a rigorous quality control protocol in place for each step of the way. Prior to installation, the drivers’ characteristics are measured to ensure that each pair of headphones will feature an identical frequency response curve of +/-0.5dB. Following assembly, another round of tests is run for each pair of headphones.

In what ways is designing a headphone driver different from designing a speaker driver?

Unlike speakers, headphones feature wideband drivers. Our competitors opt for flexible cones without a surround. This approach is problematic in that the resonant frequency of the driver’s mobile unit is too high, and resonators are needed to improve bass frequency response. In addition, a flexible cone is quick to fragment frequencies, and mids and highs are thus altered. Lastly, a cone without a surround creates compression. The drivers Focal uses for its Utopia, Elear and Clear headphones do not have any of these flaws. They adhere to our philosophy: a very light and stiff diaphragm design. Focal has also developed three other innovative technologies: the M-shaped diaphragm, an extremely thin surround, and a very wide, high coil which matches the lightness of a standard coil.

What has been Focal’s approach to developing the sound signature of its headphones?

We take a lot of measurements, and we know how to adjust the frequency response of our headphones in such as way so as to obtain a perfectly neutral delivery. Our headphones actually do not have a linear frequency response. No amount of measurement is sufficient to judge a product’s performance, whether it be headphones or a speaker. We have many listening sessions in the company of Focal’s Product Manager, during which we seek out the same sensations and tonal balance as offered by our reference speakers, such as the Utopia Evo or Sopra.

Why did Focal choose an open-back structure for its Elear, Clear and Utopia headphones?

Open-back headphones generally offer a more natural, precise listening experience with a more realistic soundstage… yet their bass performance is often lacking or tainted by distortion. Meanwhile, the isolation they offer leaves much to be desired. Closed-back headphones are usually the opposite. Thanks to the characteristics of our drivers, and specifically their ability to restitute infrabass frequencies with very little distortion, we have chosen an atypical open-back design in order to reproduce the conditions of a natural listening experience. The combination of our drivers and our open-back headphone design allows us to offer a very realistic, ultra-precise listening experience without making sacrifices in the infrabass.

What power rating does an amplifier need to have in order to drive the Elear, Clear and Utopia headphones?

The drivers installed in our Elear, Clear and Utopia headphones have been designed to be particularly easy to drive, thanks to their ultra-powerful motors and light mobile units. As such, they do not require a lot of power to attain high volume levels (104dB for 1 mW). Thanks to their high sensitivity, they can be driven by your average digital audio player. The Clear, with its lower impedance rating, is an even better match for such devices. To circumvent volume limitations, we recommend amplifiers with a power rating of at least 100 mW. Above all, we recommend using high-quality audio devices which offer very high resolution, as our headphones are capable of extracting the smallest details, nuances and dynamics from the incoming audio signal.

For Focal, are the aesthetic aspects of a pair of headphones as important as its musicality?

Design is very important for us. We want to make headphones that offer exceptional performance in addition to an attractive design. From the very beginning of each project, we are in constant interaction with our designers. They build their designs step-by-step as each model is developed, and they take into account different sets of constraints related to the acoustic, mechanical, and ergonomic aspects, in addition to comfort.